Pituitary I Flashcards
What size are microadenomas and macroadenomas?
Microadenoma <= 1cm
Macroadenoma >1cm
What can a non-functioning pituitary adenoma cause?
Compression of optic chiasm and other structures, hypoadrenalism, hypothyroidism, hypogonadism, diabetes insipidus, GH deficiency
How are non-functioning pituitary adenomas managed?
Transsphenoidal surgery, replace hormones
What are physiological causes of raised prolactin?
Breast feeding, pregnancy, sleep, stress
What drugs can cause raised prolactin?
Dopamine antagonists, antipsychotics, antidepressants, oestrogen, cocaine
What are some pathologies that cause raised prolactin?
Hypothyroidism, stalk lesions, prolactinoma
What are the symptoms of a prolactinoma in a female?
Early presentation, galactorrhoea, menstrual irregularity, amenorrhoea, infertility
What are the symptoms of a prolactinoma in a male?
Late presentation, impotence, visual field abnormalities, headache, anterior pituitary malfunction
What investigations can be done for prolactinomas?
Serum prolactin concentration (raised)
MRI = micro/macroprolactinoma, pituitary stalk, optic chiasm
Visual fields = bilateral hemianopia
Pituitary function tests
What drug can be used to treat prolactinomas?
Dopamine antagonists = bromocriptine (3x daily orally), quinagolide (once daily orally), cabergoline (usually used, least side effects, once/twice week orally)
How successful are dopamine agonists in treating prolactinomas?
Very = prolactin normalised in 96%, menstruation regained in 94%, pregnancy rate 91%, tumour shrinkage
What are the side effects of prolactinomas?
Nausea/vomiting, low mood, fibrosis (heart valves/retroperitoneal)
What causes acromegaly?
Excess GH
What are the features of acromegaly?
Giant, thickened soft tissue (large jaw and hands), sweaty, snoring/sleep apnoea, hypertension, cardiac failure, headaches, diabetes, visual field abnormalities, hypopituitarism, early CV death, colonic polyps/cancer
How is acromegaly diagnosed?
IGF-1 = age and sex matched
GTT = suppression test, 75g oral then check GH at 0/30/60/90/120mins (GH unchanged, paradoxical rise)
Visual field and pituitary function tests
CT or MRI pituitary scan
How successful is surgery in treating acromegaly?
90% cure if microadenoma, 50% cure if macroadenoma
How successful is radiotherapy alone in treating acromegaly?
25% success at three years
What drugs can be used to treat acromegaly?
Somatostatin analogues = sandostatin LAR, lanreotide
Dopamine agonists = cabergoline
Pegvisomat = GH antagonist
What are some features of somatostatin analogues used to treat acromegaly?
Reduces GH in most patients
Tumour shrinkage = 30-50% decrease in size, takes 6-12 months, re-expansion 6 weeks after stopping
How are somatostatin analogues used to treat acromegaly pre-operatively?
Relieves headaches within 1hr, improves outcomes
What are some side effects of somatostatin analogues?
Local stinging, flatulence, diarrhoea, abdominal pains, gallstones (60%, occur by 6 months, risk of biliary colic)
What is the dosage of somatostatin analogues when treating acromegaly?
Sandostatin LAR = 10-30mg/28 days IM
Lanreotide autogel = 60-12-mg/28days SC
Pasireotide LAR = 40-60mg/28days IM
What are some features of dopamine agonists used to treat acromegaly?
Cabergoline up to 3g weekly, work in around 10-15%, better if co-secreting prolactin
What are some features of pegvisomat used to treat acromegaly?
SC injection 10-30mg daily, 85% response rate, tumour size doesn’t decrease, IGF-1 decreases but serum GH increases, last line treatment
What must be managed in patients with acromegaly?
Cancer surveillance = colon and tubo-villous adenoma
CV risk factor management
